/Engine/Source/Editor/SubobjectDataInterface/Public/SubobjectDataSubsystem.h
Add a new subobject as a child to the given parent objectFSubobjectDataHandleHandle to the newly created subobject, Invalid handle if creation failed
[FSubobjectDataHandle](API\Editor\SubobjectDataInterface\FSubobjectDataHandle) AddNewSubobject ( const [FAddNewSubobjectParams](API\Editor\SubobjectDataInterface\FAddNewSubobjectParams) & Params, [FText](API\Runtime\Core\Internationalization\FText) & FailReason )